puma-rails

puma-rails is a simple gem that sets the default server for rack (and rails) to puma.

puma-rails overrides the Rack::Handler.default method to return Rack::Handler::Puma which will cause rack (and rails) to use puma by default.

Add this line to your application's Gemfile:

gem "puma-rails"

And then bundle:

$ bundle install

Also, puma is a dependency of puma-rails so you don't need a gem 'puma' entry in your Gemfile.

There's no version of puma set in puma-rails so you can use whatever version you want by either adding an entry in your Gemfile or installing it manually with gem install puma -v=2.10.2 before you bundle.

Add the puma-rails gem to your Gemfile and then rails server will default to using puma.

$ rails s
=> Booting Puma
=> Rails 3.2.21 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Puma 2.11.1 starting...
* Min threads: 0, max threads: 16
* Environment: development
* Listening on tcp://0.0.0.0:3000